Basic checks on file to ensure it's an mdb database. bug # 587739

src/extras/mdb-dump.c

@@ -58,8 +58,8 @@ int main(int argc, char **argv)
    } 
    fseek(in,(pg*pg_size),SEEK_SET);
    i = 0;
-   while (length = fread(data,1,16,in)) {
-      sprintf(addr, "%06x", i);
+   while ((length = fread(data,1,16,in))) {
+      sprintf(addr, "%06lx", i);
       //if (!strcmp(&addr[3],"000") || (!jet4 && !strcmp(&addr[3],"800")) &&
 		      //pg) break;
       if (!strcmp(&addr[3],"000") || (!jet4 && !strcmp(&addr[3],"800"))) {

src/libmdb/catalog.c

@@ -71,6 +71,8 @@ int type;
  /* mdb_table_dump(&msysobj); */
 
  table = mdb_read_table(&msysobj);
+ if (!table) return NULL;
+
  mdb_read_columns(table);
 
  mdb_bind_column(table, 1, parentid);

src/libmdb/file.c

@@ -106,18 +106,25 @@ MdbFile *f;
 		fprintf(stderr,"Couldn't open file %s\n",f->filename); 
 		return NULL;
 	}
-	f->refs++;
 	if (!mdb_read_pg(mdb, 0)) {
 		fprintf(stderr,"Couldn't read first page.\n");
 		return NULL;
 	}
+	if (mdb->pg_buf[0] != 0) {
+		close(f->fd);
+		return NULL; 
+	}
 	f->jet_version = mdb_pg_get_int32(mdb, 0x14);
 	if (IS_JET4(mdb)) {
 		mdb->fmt = &MdbJet4Constants;
-	} else {
+	} else if (IS_JET3(mdb)) {
 		mdb->fmt = &MdbJet3Constants;
+	} else {
+		fprintf(stderr,"Unknown Jet version.\n");
+		return NULL; 
 	}
 
+	f->refs++;
 	return mdb;
 }
 MdbHandle *mdb_open(char *filename)

src/libmdb/table.c

@@ -55,6 +55,8 @@ int rownum, row_start, row_end;
 	table = mdb_alloc_tabledef(entry);
 
 	mdb_read_pg(mdb, entry->table_pg);
+	if (mdb->pg_buf[0] != 0x02) return NULL; /* not a valid table def page */
+
 	len = mdb_pg_get_int16(mdb,8);
 
 	table->num_rows = mdb_pg_get_int32(mdb, fmt->tab_num_rows_offset);

src/util/mdb-export.c

@@ -97,7 +97,10 @@ main(int argc, char **argv)
 		exit(1);
 	}
 	
-	mdb_read_catalog(mdb, MDB_TABLE);
+ 	if (!mdb_read_catalog (mdb, MDB_TABLE)) {
+		fprintf(stderr,"File does not appear to be an Access database\n");
+		exit(1);
+	}
 
 	for (i=0;i<mdb->num_catalog;i++) {
 		entry = g_ptr_array_index(mdb->catalog,i);

src/util/mdb-schema.c

@@ -74,9 +74,11 @@ main (int argc, char **argv)
 	}
  }
 
- /* read the catalog */
- 
- mdb_read_catalog (mdb, MDB_TABLE);
+	/* read the catalog */
+ 	if (!mdb_read_catalog (mdb, MDB_TABLE)) {
+		fprintf(stderr,"File does not appear to be an Access database\n");
+		exit(1);
+	}
 
  /* loop over each entry in the catalog */
 

src/util/mdb-tables.c

@@ -65,7 +65,10 @@ int opt;
 	
 
  	/* read the catalog */
- 	mdb_read_catalog (mdb, MDB_TABLE);
+ 	if (!mdb_read_catalog (mdb, MDB_TABLE)) {
+		fprintf(stderr,"File does not appear to be an Access database\n");
+		exit(1);
+	}
 
  	/* loop over each entry in the catalog */
  	for (i=0; i < mdb->num_catalog; i++) {